Methods of forming conductive contacts to conductive structures, and integrated circuitry

ABSTRACT

A method of forming a conductive contact to a conductive structure includes forming a conductive structure received within and projecting outwardly from a first insulative material. A second different insulative material is deposited. The second insulative material is anisotropically etched effective to form a sidewall etch stop for the conductive structure. A third insulative material is deposited over the conductive structure and the sidewall etch stop. The third insulative material is different in composition from the second insulative material. A contact opening is etched through the third insulative material to the conductive structure using an etch chemistry which is substantially selective to the second insulative material of the sidewall etch stop. Integrated circuitry independent of the method of fabrication is disclosed.

TECHNICAL FIELD

[0001] This invention relates to methods of forming conductive contactsto conductive structures, and to integrated circuitry.

BACKGROUND OF THE INVENTION

[0002] Semiconductor wafer processing in the fabrication of integratedcircuitry typically includes the formation of contact openings withininsulating layers to underlying conductive structures. Currently, suchprocessing is typically conducted by photolithography wherein a maskinglayer is deposited and a desired pattern of openings is formedtherethrough. The masking layer is then used as a mask while chemicaletching is conducted through the mask openings into the underlyinginsulative material to etch it largely selective to the masking layersuch that the openings can be extended through the insulating materialto the conductive structures therebeneath.

[0003] The intent, of course, is to very precisely align the reticle orother device used to form the desired opening patterns within themasking layer. If the opening are misaligned, the openings to be etchedwithin the insulating layer(s) might include portions which extendlaterally beyond the desired boundary of the conductive structure towhich the openings are being etched. This can undesirably lead toetching of insulating material laterally of the conductive structure andsometimes lead to undesired exposure of other conductive structures.When the contact openings are filled with conductive material, this canof course lead to fatal shorts in the circuitry.

[0004] One prior art method of minimizing or attempting to prevent thistendency is to provide a thin blanket etch stop layer over theconductive structure prior to providing a thicker insulative materiallayer through which the primary contacts are intended to be made to theconductive structures. However, another masking step is typicallyutilized to make contact openings within the etch stop layer prior toprovision of the thicker insulative layer thereover. The typical thinnature of the blanket deposited and photopatterned etch stop layer issuch that a chemistry can typically be selected to etch the etch stoplayer largely selective relative to the underlying conductive materialand other insulative material beneath the etch stop layer. Subsequently,the etch stop layer will provide a degree of protection for mis-alignedcontact openings being etched into the overlying insulative layer.

[0005] The following invention was motivated in addressing the aboveidentified problems, although such is in no way so limited. Theinvention is limited only by the accompanying claims as literally wordedwithout limiting reference to the specification, and in accordance withthe doctrine of equivalence.

SUMMARY

[0006] The invention includes methods of forming conductive contacts toconductive structures, and to integrated circuitry. In oneimplementation, a method of forming a conductive contact to a conductivestructure includes forming a conductive structure received within andprojecting outwardly from a first insulative material. A secondinsulative material is deposited over the conductive structure. Thesecond insulative material is different in composition from the firstinsulative material. The second insulative material is anisotropicallyetched effective to form a sidewall etch stop for the conductivestructure. A third insulative material is deposited over the conductivestructure and the sidewall etch stop. The third insulative material isdifferent in composition from the second insulative material. A contactopening is etched through the third insulative material to theconductive structure using an etch chemistry which is substantiallyselective to the second insulative material of the sidewall etch stop.

[0007] In one implementation, integrated circuitry includes a pluralityof conductive structures received within and projecting outwardly from afirst insulative material. A plurality of isolated insulative collars isreceived about the conductive structures and over the first insulativematerial. The insulative collars comprise a material different from thefirst insulative material. A third insulative material is received overthe conductive structures and insulative collars. The third insulativematerial is different from the collar material. A plurality ofconductive contacts are formed to the conductive structures through thethird insulative material.

[0008] In one implementation, integrated circuitry includes a conductiveline received within and projecting outwardly from a first insulativematerial. The conductive line includes opposing sidewall portions whichproject outwardly from the first insulative material. A pair ofinsulative sidewall spacers is received over the sidewall portions andover the first insulative material. The sidewall spacers comprise amaterial different from the first insulative material. A thirdinsulative material is received over the conductive line and thesidewall spacers. The third insulative material is different from thesidewall spacer material. A conductive contact is formed to theconductive line through the third insulative material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

[0010]FIG. 1 is a diagrammatic perspective view of a semiconductor waferfragment/section in process in accordance with an aspect of theinvention.

[0011]FIG. 2 is a view of the FIG. 1 wafer fragment at a processing stepsubsequent to that shown by FIG. 1.

[0012]FIG. 3 is a view of the FIG. 2 wafer fragment at a processing stepsubsequent to that shown by FIG. 2.

[0013]FIG. 4 is a view of the FIG. 3 wafer fragment at a processing stepsubsequent to that shown by FIG. 3.

[0014]FIG. 5 is a top plan view of a larger portion of the waferfragment in process, and corresponding in sequence to the processing ofFIG. 4.

[0015]FIG. 6 is a view of the FIG. 4 wafer fragment at a processing stepsubsequent to that shown by FIG. 4.

[0016]FIG. 7 is a view of the FIG. 6 wafer fragment at a processing stepsubsequent to that shown by FIG. 6.

[0017]FIG. 8 is a view of the FIG. 7 wafer fragment at a processing stepsubsequent to that shown by FIG. 7.

[0018]FIG. 10 is a diagrammatic perspective view of anothersemiconductor wafer fragment/section in process in accordance with anaspect of the invention FIG. 11 is a view of the FIG. 10 wafer fragmentat a processing step subsequent to that shown by FIG. 10.

[0019]FIG. 12 is a view of the FIG. 11 wafer fragment at a processingstep subsequent to that shown by FIG. 11.

[0020]FIG. 13 is a view of the FIG. 12 wafer fragment at a processingstep subsequent to that shown by FIG. 12.

[0021]FIG. 14 is a view of the FIG. 13 wafer fragment at a processingstep subsequent to that shown by FIG. 13.

[0022]FIG. 15 is a view of the FIG. 14 wafer fragment at a processingstep subsequent to that shown by FIG. 14.

[0023]FIG. 16 is a view of the FIG. 15 wafer fragment at a processingstep subsequent to that shown by FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] This disclosure of the invention is submitted in furtherance ofthe constitutional purposes of the U.S. Patent Laws “to promote theprogress of science and useful arts” (Article 1, Section 8).

[0025] One first preferred embodiment of a method of forming aconductive contact to a conductive structure, and integrated circuitryindependent of the method of fabrication, is described with reference toFIGS. 1-8. FIG. 1 depicts a semiconductor wafer fragment 10 comprisingof bulk monocrystalline substrate 12 having trench isolation regions 14form therein. In the context of this document, the term “semiconductorsubstrate” or “semiconductive substrate” is defined to mean anyconstruction comprising semiconductive material, including, but notlimited to, bulk semiconductive materials such as a semiconductive wafer(either alone or in assemblies comprising other materials thereon), andsemiconductive material layers (either alone or in assemblies comprisingother materials). The term “substrate” refers to any supportingstructure, including, but not limited to, the semiconductive substratesdescribed above. Also in the context of this document, the terms “layer”and “material” encompass both the singular and the plural unlessotherwise indicated.

[0026]FIG. 1 depicts partial fabrication of exemplary DRAM circuitry,with the depicted cross section showing a pair of DRAM memory cells. Anexemplary material for substrate 12 is bulk monocrystalline silicon. Aseries of four wordlines 16 are shown formed over substrate 12/14. Aseries of diffusion regions 17, 18 and 19 are received within substrate12 between isolation regions 14 and wordlines 16. Diffusion regions 17,19, or source/drain regions 17, 19, will connect with storage nodes ofstorage capacitors, while diffusion region 18 will connect with a bitline.

[0027] A first insulative material 20 is deposited over the substrate,and is planarized. Material 20 may be homogenous, or comprise aplurality of different materials or layers. An exemplary preferredprimary composition for material 20 is borophosphosilicate glass (BPSG).Contact openings 21, 22 and 23 have been formed through first insulativematerial 20 to proximate diffusion region 17, 18, 19, respectively. Suchhave been filled with conductive material to form a plurality ofconductive structures 24, 25 and 26. An exemplary height/elevation abovethe diffusion regions for structures 24, 25 and 26 is from 1,000Angstroms to 10,000 Angstroms. Such in the preferred embodimentaccordingly project outwardly from diffusion region 17, 18, 19,respectively. Material or materials to form structures 24, 25 and 26comprise one or more metals, metal compounds, conductively dopedsemiconductive materials, and mixtures thereof. The preferred embodimentimplementation of FIG. 1 depicts projections 24, 25 and 26 in the formof upstanding pillars. Such provides but one exemplary embodiment informing a conductive structure which projects outwardly relative to someunderlying substrate. Pillars 24, 25 and 26 can be considered as havingsome outer region 28 the lateral portions of which are surrounded byfirst insulative material 20. In the illustrated and preferredembodiment, first insulative material 20 contacts projections 24, 25 and26, and outer portions 28. Such provides but one exemplary embodiment ofproviding first insulative material proximate a conductive structure andover underlying substrate.

[0028] Referring to FIG. 2, a portion of first insulative material 20 isremoved effective to expose respective opposing sidewall portions 30, 31of the respective conductive structures, and leave the conductivestructures 24, 25 and 26 projecting outwardly from first insulativematerial 20. The removing is preferable conducted by chemical etching.Such provides but one example of forming one or more conductivestructures received within and projecting outwardly from a firstinsulative material. An exemplary preferred etching will leave from 500Angstroms to 5,000 Angstroms (about 2,000 Angstroms being morepreferred) of structures 24, 25 and 26 exposed above material 20.

[0029] Referring to FIG. 3, a second insulative material 34 is depositedover first insulative material 20 and conductive structures 24, 25, and26 projecting outwardly therefrom. Second insulative material isdifferent in composition from first insulative material 20. Where firstinsulative material 20 principally comprises an oxide such as BPSG, anexemplary preferred composition for material 34 is an insulativenitride, for example silicon nitride. An exemplary preferred depositionthickness range for layer 34 is from 100 Angstroms to 2,000 Angstroms.Preferably as shown, second insulative material 34 contacts conductivesidewall portions 30/31.

[0030] Referring to FIGS. 4 and 5, second insulative material 34 isanisotropically etched to form a sidewall etch stop 36 for theindividual conductive structures. Any suitable chemistry, whetherexisting or yet-to-be-developed can be used. For example to etch siliconoxide or silicon nitride in a dry etch, one or more of a fluorocarbon orhydrofluorocarbon primary gas along with one or more secondary gasessuch as oxygen, nitrogen, or argon can be used. In the illustrated andpreferred embodiment where the conductive structure is a pillar, theanisotropic etching preferably forms the sidewall etch stop 36 in theform of a series of interconnected collars which are received about therespective conductive pillars. FIG. 5 depicts a larger portion of thesemiconductor wafer fragment in top perspective view showing a pluralityof isolated etch stop collars 36 which are received about the conductivestructures, which in this preferred embodiment constitute conductivepillars. As shown, at least some of the isolated etch stop collars 36are formed to collar multiple conductive structures which projectoutwardly from first insulative material 20. The anisotropic etching oflayer 34 is preferable conducted without providing any masking over anyof substrate 10 during such etching.

[0031] Referring to FIG. 6, a third insulative material 40 is formedover conductive structures 24, 25 and 26 and sidewall etch stops 36.Third insulative material 40 is different in composition from secondinsulative material 34. First insulative material 20 and thirdinsulative material 40 may be of the same composition, or may not be ofthe same composition. Further by way of example only, both may comprisethe same or different oxides. One preferred embodiment forms secondinsulative material 34 to comprise an insulative nitride, and insulativematerials 20 and 40 to comprise the same or different oxides. Onespecific preferred embodiment is to form layers 20 and 40 to compriseBPSG, and material 34 to comprise silicon nitride.

[0032] Referring to FIG. 7, contact openings 42, 44 and 46 are etchedthrough third insulative material 40 to conductive structures 24, 25 and26, respectively, using an etch chemistry which is substantiallyselective to second insulative material 34 of sidewall etch stops 36. Inthe context of this document, “substantially selective” means an etchratio of one material to another of at least 2:1. The depictedprocessing shows openings 42, 44 and 46 being slightly misaligned to theright whereby such etching does ultimately expose sidewall etch stop 36.

[0033] Referring to FIG. 8, contact openings 42, 44 and 46 are at leastpartially filled with conductive material, thereby forming conductivecontacts 48, 50 and 52 to conductive structures 24, 25 and 26 throughthird insulative material 40. In the depicted and preferred embodiments,contacts 48 and 52 constitute storage node capacitor plates, whilecontact 50 constitutes a plugging material for ultimate connection witha bit line in the depicted DRAM circuitry. Any existing oryet-to-be-developed processing(s) can be conducted to complete thecircuitry fabrication.

[0034] But one additional alternative embodiment of many is nextdescribed with reference to FIGS. 9-16. Like numerals from the firstdescribed embodiment are utilized where appropriate, with differencesbeing indicated with a suffix “a” or with different numerals. FIG. 9depicts a semiconductor wafer fragment 10 a having a first insulativematerial 20 a formed over a bulk substrate 12 a. A trough 60 has beenformed in first insulative material 20 a into some desired conductiveline shape.

[0035] Referring to FIG. 10, trough 60 has been at least partiallyfilled with conductive material 62 effective to form a conductive linewithin trough 60. Any conductive metal, metal compound, alloy orconductively doped semiconductive material, or mixtures thereof, mightbe utilized.

[0036] Referring to FIG. 11, only some of first insulative material 20 ais removed, preferably by chemical etching, effective to expose sidewallportions 64, 65 of conductive line 62. Again, such provides but oneexample of forming a conductive structure received within and projectingoutwardly from a first insulative material, with the conductivestructure here being in the form of a conductive line.

[0037] Referring to FIG. 12, a second insulative material 34 a isdeposited over conductive line 62, exposed sidewall portion 64, 65thereof, and first insulative material 20 a. Second insulative material34 a is different in composition from first insulative material 20 a.Exemplary materials and relationships are as those described above withrespect to materials 20 and 34. Preferably, second insulative material34 a contacts exposed sidewall portions 64 and 65.

[0038] Referring to FIG. 13, second insulative material 34 a isanisotropically etched effective to form sidewall etch stop spacers 36 aover sidewall portions of insulative line 62 and over first insulativematerial 20 a.

[0039] Referring to FIG. 14, a third insulative material 40 a isdeposited over conductive line 62 and sidewall etch stop spacers 36 a.Third insulative material 40 a is different in composition from secondinsulative material 34 a. Exemplary preferred materials andrelationships relative to third insulative material 40 a are asdescribed above with respect to material 40.

[0040] Referring to FIG. 15, a contact opening 70 is etched throughthird insulative material 40 a to conductive line 62 using an etchchemistry which is substantially selective to second insulative material34 a of sidewall etch stop spacer 36 a. Contact opening 70 is shownbeing slightly misaligned such that the etching of its formationultimately exposes one of etch stop spacers 36 a.

[0041] Referring to FIG. 16, conductive material 72 is formed withincontact opening 70, thereby in the illustrated embodiment forming aconductive contact to conductive line 62 through third insulativematerial 40 a.

[0042] The invention also contemplates integrated circuitry independentof the method of fabrication.

[0043] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

1. A method of forming a conductive contact to a conductive structure,comprising: forming a conductive structure received within andprojecting outwardly from a first insulative material; depositing asecond insulative material over the conductive structure, the secondinsulative material being different in composition from the firstinsulative material; anisotropically etching the second insulativematerial effective to form a sidewall etch stop for the conductivestructure; depositing a third insulative material over the conductivestructure and the sidewall etch stop, the third insulative materialbeing different in composition from the second insulative material; andetching a contact opening through the third insulative material to theconductive structure using an etch chemistry which is substantiallyselective to the second insulative material of the sidewall etch stop.2. The method of claim 1 wherein the first and third insulativematerials are of the same composition.
 3. The method of claim 1 whereinthe first and third insulative materials are not of the samecomposition.
 4. The method of claim 1 wherein the second insulativematerial comprises a nitride, and the first and third insulativematerials comprise oxides.
 5. The method of claim 4 wherein the oxidesare the same composition.
 6. The method of claim 4 wherein the oxidesare not of the same composition.
 7. The method of claim 1 wherein theconductive structure is a conductive line.
 8. The method of claim 1wherein the conductive structure is a conductive pillar.
 9. The methodof claim 1 further comprising at least partially filling the contactopening with conductive material.
 10. The method of claim 1 wherein thecontact opening etching exposes the sidewall etch stop.
 11. The methodof claim 1 wherein the anisotropic etching is conducted without anypatterned masking layer being received over the second insulativematerial during the anisotropic etching.
 12. A method of forming aconductive contact to a conductive structure, comprising: forming aconductive structure projecting outwardly from a substrate; providing afirst insulative material over the substrate and proximate thestructure; removing a portion of the first insulative material effectiveto expose opposing sidewall portions of the conductive structure, andleave the conductive structure projecting outwardly from the firstinsulative material; depositing a second insulative material over thefirst insulative material and the conductive structure projectingoutwardly therefrom, the second insulative material being different incomposition from the first insulative material; anisotropically etchingthe second insulative material effective to form a sidewall etch stopfor the conductive structure; depositing a third insulative materialover the conductive structure and the sidewall etch stop, the thirdinsulative material being different in composition from the secondinsulative material; and etching a contact opening through the thirdinsulative material to the conductive structure using an etch chemistrywhich is substantially selective to the second insulative material ofthe sidewall etch stop.
 13. The method of claim 12 wherein the removingcomprises chemical etching.
 14. The method of claim 12 wherein thesecond insulative material contacts the conductive sidewall portions.15. The method of claim 12 wherein the anisotropically etching forms thesidewall etch stop in the form of an insulative collar which surroundsthat portion of the conductive structure projecting from the firstinsulative material.
 16. The method of claim 12 wherein the conductivestructure comprises a conductive line, and the anisotropically etchingforms the sidewall etch stop in the form of a pair of etch stop spacerson opposing sides of the conductive line.
 17. The method of claim 12wherein the contact opening etching exposes the sidewall etch stop. 18.The method of claim 12 wherein the anisotropic etching is conductedwithout any patterned masking layer being received over the secondinsulative material during the anisotropic etching.
 19. A method offorming a conductive contact to a conductive structure, comprising:forming a trough in a first insulative material into a desiredconductive line shape; at least partially filling the trough withconductive material effective to form a conductive line therewithin;removing only some of the first insulative material effective to exposesidewall portions of the conductive line; depositing a second insulativematerial over the conductive line exposed sidewall portions, the secondinsulative material being different in composition from the firstinsulative material; anisotropically etching the second insulativematerial effective to form a sidewall etch stop spacer on the conductiveline; depositing a third insulative material over the conductive lineand the sidewall etch stop spacer, the third insulative material beingdifferent in composition from the second insulative material; andetching a contact opening through the third insulative material to theconductive line using an etch chemistry which is substantially selectiveto the second insulative material of the sidewall etch stop spacer. 20.The method of claim 19 wherein the second insulative material contactsthe conductive sidewall portions.
 21. The method of claim 19 wherein thefirst and third insulative materials are of the same composition. 22.The method of claim 19 wherein the first and third insulative materialsare not of the same composition.
 23. The method of claim 19 wherein thesecond insulative material comprises a nitride, and the first and thirdinsulative materials comprise oxides.
 24. The method of claim 19 whereinthe contact opening etching exposes the sidewall etch stop spacer. 25.The method of claim 19 wherein the anisotropic etching is conductedwithout any patterned masking layer being received over the secondinsulative material during the anisotropic etching.
 26. A method offorming a conductive contact to a conductive structure, comprising:forming a conductive pillar projecting outwardly from a diffusion regionof a semiconductor substrate, the conductive pillar including an outerregion lateral portions of which are surrounded by a first insulativematerial; removing only some of the first insulative material effectiveto expose sidewall portions of the outer region of the conductivepillar; depositing a second insulative material over the exposedsidewall portions of the conductive pillar, the second insulativematerial being different in composition from the first insulativematerial; anisotropically etching the second insulative materialeffective to form a sidewall etch stop collar about the conductivepillar; depositing a third insulative material over the conductivepillar and the sidewall etch stop collar, the third insulative materialbeing different in composition from the second insulative material; andetching a contact opening through the third insulative material to theconductive pillar using an etch chemistry which is substantiallyselective to the second insulative material of the sidewall etch stopcollar.
 27. The method of claim 26 wherein the second insulativematerial contacts the conductive sidewall portions.
 28. The method ofclaim 26 wherein the removing comprises chemical etching.
 29. The methodof claim 26 wherein the first and third insulative materials are of thesame composition.
 30. The method of claim 26 wherein the first and thirdinsulative materials are not of the same composition.
 31. The method ofclaim 26 wherein the second insulative material comprises a nitride, andthe first and third insulative materials comprise oxides.
 32. The methodof claim 26 wherein the contact opening etching exposes the sidewalletch stop collar.
 33. The method of claim 26 wherein the anisotropicetching is conducted without any patterned masking layer being receivedover the second insulative material during the anisotropic etching. 34.A method of forming a conductive contacts to conductive structures,comprising: forming a plurality of conductive structures received withinand projecting outwardly from a first insulative material; depositing asecond insulative material over the first insulative material and theconductive structures projecting outwardly therefrom, the secondinsulative material being different in composition from the firstinsulative material; anisotropically etching the second insulativematerial effective to form a plurality of isolated etch stop collarsreceived about the conductive structures; depositing a third insulativematerial over the conductive structures and etch stop collars, the thirdinsulative material being different in composition from the secondinsulative material; and etching contact openings through the thirdinsulative material to the conductive structures using an etch chemistrywhich is substantially selective to the second insulative material ofthe etch stop collars.
 35. The method of claim 34 wherein at least someof the isolated etch stop collars are formed to collar multipleconductive structures projecting outwardly from the first insulativematerial.
 36. The method of claim 34 wherein the conductive structurescomprise conductive pillars.
 37. The method of claim 34 wherein theconductive structures comprise conductive pillars projecting fromdiffusion regions formed within semiconductive material of a bulksemiconductive substrate.
 38. The method of claim 34 wherein the firstand third insulative materials are of the same composition.
 39. Themethod of claim 34 wherein the first and third insulative materials arenot of the same composition.
 40. The method of claim 34 wherein thesecond insulative material comprises a nitride, and the first and thirdinsulative materials comprise oxides.
 41. The method of claim 34 whereinthe contact openings etching exposes at least some of the sidewall etchstop collars.
 42. The method of claim 34 wherein the anisotropic etchingis conducted without any patterned masking layer being received over thesecond insulative material during the anisotropic etching. 43.Integrated circuitry comprising: a plurality of conductive structuresreceived within and projecting outwardly from a first insulativematerial; a plurality of isolated insulative collars received about theconductive structures and over the first insulative material, theinsulative collars comprising a material different from the firstinsulative material; a third insulative material received over theconductive structures and insulative collars, the third insulativematerial being different from the collar material; and a plurality ofconductive contacts formed to the conductive structures through thethird insulative material.
 44. The integrated circuitry of claim 43wherein the conductive structures comprise conductive pillars.
 45. Theintegrated circuitry of claim 43 wherein the conductive structurescomprise conductive pillars projecting from diffusion regions formedwithin semiconductive material of a bulk semiconductive substrate. 46.The integrated circuitry of claim 43 wherein the conductive structurescomprise conductive pillars projecting from diffusion regions formedwithin semiconductive material of a bulk semiconductive substrate ofDRAM integrated circuitry.
 47. The integrated circuitry of claim 43wherein at least some of the isolated insulative collars collar multipleconductive structures.
 48. The integrated circuitry of claim 43 whereinthe first and third insulative materials are of the same composition.49. The integrated circuitry of claim 43 wherein the first and thirdinsulative materials are not of the same composition.
 50. The integratedcircuitry of claim 43 wherein the collars comprise a nitride, and thefirst and third insulative materials comprise oxides.
 51. The integratedcircuitry of claim 50 wherein the oxides are the same composition. 52.The integrated circuitry of claim 50 wherein the oxides are not of thesame composition.
 53. The integrated circuitry of claim 43 wherein theinsulative collars contact the conductive structures.
 54. Integratedcircuitry comprising: a conductive line received within and projectingoutwardly from a first insulative material, the conductive lineincluding opposing sidewall portions which project outwardly from thefirst insulative material; a pair of insulative sidewall spacersreceived over the sidewall portions and over the first insulativematerial, the sidewall spacers comprising a material different from thefirst insulative material; a third insulative material received over theconductive line and the sidewall spacers, the third insulative materialbeing different from the sidewall spacer material; and a conductivecontact formed to the conductive line through the third insulativematerial.
 55. The integrated circuitry of claim 54 wherein the pair ofinsulative sidewall spacers contact the sidewall portions.
 56. Theintegrated circuitry of claim 54 wherein the first and third insulativematerials are of the same composition.
 57. The integrated circuitry ofclaim 54 wherein the first and third insulative materials are not of thesame composition.
 58. The integrated circuitry of claim 54 wherein theinsulative sidewall spacers comprise a nitride, and the first and thirdinsulative materials comprise oxides.
 59. The integrated circuitry ofclaim 58 wherein the oxides are the same composition.
 60. The integratedcircuitry of claim 58 wherein the oxides are not of the samecomposition.